Photovoltaic power generation systems are divided into independent photovoltaic power generation systems, grid-connected photovoltaic power generation systems and distributed photovoltaic power generation systems.
1. Independent photovoltaic power generation is also called off-grid photovoltaic power generation. It is mainly composed of solar cell modules, controllers, and batteries. If you want to power AC loads, you also need to configure an AC inverter. Independent photovoltaic power stations include village power supply systems in remote areas, solar household power supply systems, communication signal power supplies, cathode protection, solar street lights and other photovoltaic power generation systems that can operate independently with batteries.
2. Grid-connected photovoltaic power generation is the direct current generated by solar panels that is converted into alternating current that meets the requirements of the municipal power grid by a grid-connected inverter and then directly connected to the public power grid.
It can be divided into grid-connected power generation systems with batteries and without batteries. The grid-connected power generation system with batteries is dispatchable and can be connected to or exit the power grid as needed. It also has the function of backup power supply, which can provide emergency power supply when the power grid is out of power for some reason. Photovoltaic grid-connected power generation systems with batteries are often installed in residential buildings; grid-connected power generation systems without batteries do not have the functions of dispatchability and backup power supply, and are generally installed on larger systems. Grid-connected photovoltaic power generation has centralized large-scale grid-connected photovoltaic power stations, which are generally national-level power stations. The main feature is that the generated energy is directly transmitted to the power grid, and the power grid is uniformly allocated to supply power to users. However, this type of power station has large investment, long construction period, and large land area, and has not yet developed much. Distributed small-scale grid-connected photovoltaics, especially photovoltaic building integrated photovoltaic power generation, are the mainstream of grid-connected photovoltaic power generation due to their advantages such as small investment, fast construction, small land area, and strong policy support.
3. Distributed photovoltaic power generation system, also known as distributed power generation or distributed energy supply, refers to the configuration of a smaller photovoltaic power generation and power supply system at the user site or near the power consumption site to meet the needs of specific users, support the economic operation of the existing distribution network, or meet both requirements at the same time.
The basic equipment of the distributed photovoltaic power generation system includes photovoltaic cell components, photovoltaic array brackets, DC junction boxes, DC distribution cabinets, grid-connected inverters, AC distribution cabinets and other equipment, as well as power supply system monitoring devices and environmental monitoring devices. Its operating mode is that under the condition of solar radiation, the solar cell module array of the photovoltaic power generation system converts the output electricity of solar energy, which is sent to the DC distribution cabinet through the DC combiner box, and then converted into AC power by the grid-connected inverter to supply the building's own load. Excess or insufficient electricity is regulated by connecting to the power grid.